• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2003.05a
• /
• pp.342-352
• /
• 2003

Idle NVH characteristics are one of the most important aspects among the vehicle performances. Vehicle developers are devoted to improve vehicle interior noise and steering wheel and seat vibrations. In order to improve the idle quality, noise and vibration transfer path should be carefully evaluated. Also, effects of various components related to the idle performance should be confirmed. A general procedure for improving the idle qualify is described in detail. The relationship among cylinder pressure characteristics, crankshaft rotational speed variation, and vehicle vibrations is also investigated. Influences of drive shaft, torque converter, air conditioning system, vehicle structure including engine mount system, and idle control parameters on the vehicle idle quality are studied. Weak points of typical vehicles on the idle qualify are identified. Some of improvement measures are proposed and verified.

• Journal of Advanced Marine Engineering and Technology
• /
• v.25 no.5
• /
• pp.1148-1160
• /
• 2001

An electronic control system of the automobile engine for optimal start and idle speed control has been developed. This system employs the microcoputer-based electronic control unit and crank angle sensor for precise control on fuel injection, ignition timing, and idle speed more quickly and accurately at the start and idling. Consequently, the number of misfire can be reduced during been affected by air flow rate, idle quality(roughness), spark timing, fuel injection, water temperature, and load, Thus, this electronic control system strivers to reach the optimal idle operating point, defined the lowest idle speed(fuel economy) and idle quality(roughness), under any engine operating conditions.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.5
• /
• pp.478-489
• /
• 2016

Recently, there has been increasing interest in the remodecycling options of idle spaces around the central city through the urban regeneration. Various studies to create new added value through this way are ongoing. This study aims to analyze the impact relationship and structure on the regeneration of idle space by types affecting the quality of residents' life and local economy revitalization. The hypothesis was verified by a suitability test for setting the hypothesis and statistical significance test from the PLS 3.0 package. The results of this study drew 6 hypotheses from a total of 11 on the 'idle space regeneration of economy based type of PLS-SEM' and 4 hypotheses from a total of 11 on the 'idle space regeneration of neighborhood regeneration type PLS-SEM'. The results can be summarized into several parts. First, if cultural aspects should be considered, the regeneration of idle space (economy-based type and neighborhood-regeneration type) could meet 2 parts, such as the quality of residents' life and local economy revitalization at the same time. Second, improving the 'physical aspects' only affects the 'idle space regeneration of the economy-based type of PLS-SEM'. Third, improving the 'social aspects' only affects the 'idle space regeneration of neighborhood regeneration type of PLS-SEM'. This study has significance in that it provides the empirical analysis for the regeneration of idle space and there are differences according to types of PLS structural model.

• Journal of Energy Engineering
• /
• v.18 no.2
• /
• pp.136-140
• /
• 2009

Vehicle idle has become an increasing quality concern for automobile manufacturers because of its impact on customer satisfaction. As demand for better fuel economy increases, automobile manufacturers are continuously looking for any benefits from different driving conditions. Combustion variability in spark ignition engines was recognized that the stability of engine at idle is affected by the factors of fuel injection timing, ignition timing and air-fuel ratio. Therefore in this research, the results will be shown the effects of stability and the variations at idle according to fuel injection timing, ignition timing and air-fuel ratio as the basic parameters.

• The Journal of the Korea Contents Association
• /
• v.16 no.2
• /
• pp.129-142
• /
• 2016

This study evaluates the sectoral effects of the regeneration of the idle space and aims to analyze the impact relationship and structure with the quality of residents's life and local economy revitalization. this study verifies the 8 hypotheses from total 11 ones through the PLS structural equation model and suitability test for setting the hypothesis and statistical significance test. The results can be summarized into 3 parts. First, If physical, social and cultural aspects should be considered, Regeneration of idle space could meet the 2 pasts such as quality of residents life and local economy revitalization at the same time. Secondly, the regeneration of idle space from environmental aspect should be led by the local government and let it's effect leaded to local economy revitalization through the collaboration of private and public sector. Finally, it should promote the quality of resident's life and let the satisfaction linked to cyclical effects with local economy revitalization. This study has an significance that it provides the theoretical basis for regeneration of idle space and it is an empirical study for impact structure model.

• The Journal of the Convergence on Culture Technology
• /
• v.7 no.1
• /
• pp.327-335
• /
• 2021

We aimed to find new space types and characteristics for creating gardens in the city through the type of idle space in the city, present guidelines that can be used in creating gardens in the future, and establish basic data for expanding green infrastructure. As a result, we found that the idle space in the city was classified into four types, and it was determined that differentiation should be given to the creation of each type. The achievements of this study can be a potential source of urban ecosystem services that can provide community benefits and opportunities for urban regeneration through the redevelopment of the community and support the health and well-being of local residents. In addition, urban idle space can be a valuable resource as a green infrastructure that can be used to support the health of urban ecosystems and improve the quality of life of urban residents.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2010.11a
• /
• pp.879-882
• /
• 2010

본 연구는 idle 상태의 단말을 위한 이종 무선 통신망 환경에서 네트워크 선택 알고리즘을 제안한다. 제안 하는 알고리즘은 셀과 사용자 각각의 상대적 상태 정보를 이용하는 프로필기반 네트워크 선택 프레임워크(Profile-based Network Selection Framework, PNSF)에 기반한다. PNSF 는 traffic status, mobility, 그리고 QoS (Quality of Service) 카테고리의 정보들을 바탕으로 셀과 사용자의 프로필을 생성한다. 생성된 프로필들을 3 차원의 프로필 공간에서 위치 시키고 각 셀과 사용자 프로필 사이의 거리를 각 카테고리를 구성하는 요소의 정적 특성을 반영하여 계산한다. 사용자는 최종적으로 가장 거리가 긴 셀을 선택하여 location update 를 수행한다. 본 연구에서 제안하는 알고리즘은 이종의 무선통신망 환경의 특성과 idle 모드의 특성을 반영하여 location update 의 발생 빈도를 합리적으로 줄이면서도 급증하는 데이터 통신 사용을 고려하여 사용자가 네트워크에 전체에 적절히 분산되도록 선택한다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2006.05a
• /
• pp.110-113
• /
• 2006

This paper describes the development process of body and full vehicle for reduced idle vibration through the data level of frequency and sensitivity. The vibration mode map is used to separate body structure modes from resonance of engine idle nm and steering system. This paper describes the analysis approach process to reduce the variation of uncertainties for idle vibration performance at initial design stage. The robust design method is performed to increase the stabilization performance under vehicle vibration. It is used to predict the effects of the stiffness deviation according to the spot welding condition of the body structure. The tolerance associated with hood over slam bumper is analyzed for the quality deviation of the moving system in full vehicle. And the glass sealant stiffness and weight difference is considered for the deviation characteristic. The design guideline is suggested considering sensitivity about body and full vehicle by using mother car at initial design stage. It makes possible to design the good NVH performance and save vehicles to be used in tests. These improvements can lead to shortening the time needed to develop better vehicles.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2007.11a
• /
• pp.359-364
• /
• 2007

Spray characteristics of the APU gas turbine engine were investigated. In order to understand blow out phenomena of the APU engine, we performed fuel spray test. In the test, four operating conditions such as sea level idle, sea level max power, 20,000 feet idle, 20,000 feet max power were used as spray experimental conditions. PDPA(phase Doppler Particle Analyzer) was used for measuring the particle diameter and velocity. Also spray visualization was performed by using ND-YAG sheet laser beam. From the test result, in the case of 20,000 feet idle condition, SMD is about 100 ${\mu}m$ and maximum particle velocity is about 10 m/s. For the flame stability, spray quality should be improved at 20,000 feet idle condition.

• Journal of KSNVE
• /
• v.7 no.4
• /
• pp.681-688
• /
• 1997

The purpose of engine mount system is to reduce the noise and vibration caused by engine vibration, and to decouple the roll and bounce mode at idle. To reduce the noise and vibration level in a vehicle, it is important to make the design optimization of engine mount system that consider the moment of inertia and inclination of mount rubber. As a result, according to the definition of Torque Roll Axis (TRA), the vibration axis at idle must be on the TRA or very close to it. In this paper, we studied the effect of the design optimization of engine mount system. And we have achieved good improvements in noise and vibration quality of F.R. vehicle.